If you think a lap pool is scary - then you don't want to know about your jacuzzi/hot tubs.
If the pool you swim at has an ozone system then you don't have to worry so much about chloramines (not only does the ozone disenfect but it also breaks down/destroys chloramines).
Lastly for indoor pools your HVAC system is very importatnt - hopefully the air circulation system isn't at the bottom of the required scale (more air movement is better).

Ok a swimming doctor (family practitioner, not a super sub specialist or toxicologist)

I read over all the posts and searched some sites (like the CDC and FDA etc) for research on this.

Everything really focuses on chlorine gas as a respiratory irritant, with little research on long term, low level exposure. If you have asthma, this may cause you problems. However, let your doctor know and most likely your medicines can be adjusted to help prevent any asthma complications associated.

Some important things to remember. Chlorine is very reactive. It sure does cause some damage, but only very quickly and locally. Your body actually USES its own natural chloride ions in specific places to help manage things like mucous (especially in the respiratory system). There are 3 main sites I can think of that chlorine the swimming pools could theoretically cause some problems.

First is the eyes. Obvious: wear your goggles.

Next is the surface area of your body. Hair: makes it tougher, strawlike and funky. Use a conditioner or something like that to remove and or block chlorine; also a swim cap. Your skin can definitely be affected, but because of the cool way our skin is put together, it really should not be able to penetrate the skin and cause any damage internally. Thus, you CANNOT kill any beneficial bacteria internally this way. You can (and will) get a local skin irritation depending on length of time in the pool, other existing skin conditions (like eczema), etc. These can be minimized or prevented by showering before getting in the water (then the little microscopic areas of your skin are full of water with less chlorine than the pool already) and using a mild lotion after (not before, it will strip clean off) getting out of the water. Shower again, however, to replace the chlorinated water before lotion.

Sorry for the length of this.

Next is respiratory. I could not find any data on long term exposure to low level chlorine levels. However, there could in theory be a chance of causing damage to some of the supporting structure of the alveoli. I must hasten to add that one of the reasons I started swimming for fitness is that the healthiest old folks I see as patients are over represented as swimmers. These are 80+ year olds whose lungs sound awesome. So weak anecdotal evidence: I doubt it is a worry.

Finally (oops I lied I came up with 4 sites) is accidental swallowing. This would be my guess as to where the funky organic chlorine molecules came from in the study cited above. Ironically enough, chlorine itself would be unlikely to cause much problem in the stomach, and is going to get neutralized as soon as it hits the small intestine anyway. However, weird organic chlorine compounds could in theory survive some digestion. Don't think about this too much or you'll be scared to get any water in your mouth next time.

Oh yeah: cancer is unlikely a risk (although never impossible), because cancers really need to come from DNA damage, and chlorine has usually already reacted to your cell membranes, epidermis, etc and "burned itself out" before it could get close to your DNA. BUT: I couldn't find much research on this, so this is largely supposition.

Summary: Swimming is great and overall probably better for you than any other exercise, even when chlorine is involved. My opinion.

i tend to itch too if the chlorine levels are up,also my eyes still get sore even with goggles,i have to re shower when i get home .chlorine however does chemically remove greater nasties than it creates..the skin has natural oils and too much bathing removes these oils,this makes you itch..i too shower before and after entering the pool

Re: Long term Health Effects

RESEARCH

In the course of preparing materials for the Swimming Science Journal, I came across the following articles concerning chlorinated pools. Abstracts of contents and appropriate comments are included below. Please read the discussion points and articles that follow the abstracts.
WHAT IS KNOWN

Exercising competitive swimmers absorb toxic levels of chlorine products in the course of a training session.

Training two or more times a day will not allow the toxins to be completely cleared from the body in most swimmers.

Children inhale more air per unit of body weight than mature persons, and have lesser developed immune and defense systems.

Young children absorb relatively greater amounts of toxins than older swimmers and therefore, are at greater risk.

In hyper-chlorinated pools, even dental enamel can be eroded because of the increased acidity in swimmers in training.

Exercise intensity and number of sessions increase the toxic concentrations in competitive swimmers.

Greater toxin absorption occurs through the skin than through breathing. However, the breathing action alone is sufficient to cause hypersensitivity and "asthma-like" respiratory conditions in at least some swimmers. The percentage of asthma-like symptoms in swimmers that is attributable to exposure to chlorinated hydrocarbons versus being unrelated to chlorine exposure is presently unknown. This is an area clearly deserving of further research.

Overchlorination is particularly hazardous to the health of swimmers.

CHILDREN DEVELOP ASTHMA IN CHLORINATED POOLS

Bernard, A., Carbonnelle, S., Michel, O., Higuet, S., de Burbure, C., Buchet, J-P., Hermans, C., Dumont, X., & Doyle, I. (2003). Lung hyperpermeability and asthma prevalence in schoolchildren: unexpected associations with the attendance at indoor chlorinated swimming pools. Occupational and Environmental Medicine, 60, 385-394.
This study assessed whether exposure to nitrogen trichloride in indoor chlorinated pools may affect the respiratory epithelium of children and increase the risk of some lung diseases such as asthma.
Healthy children (N = 226), were measured for serum surfactant associated proteins A and B (SP-A and SP-B), 16 kDa Clara cell protein (CC16), and IgE. Lung specific proteins were measured in the serum of 16 children and 13 adults before and after exposure to NCl3 in an indoor chlorinated pool. The relation between pool attendance and asthma prevalence were studied in 1881 children. Asthma was screened with the exercise induced bronchoconstriction test (EIB).
Pool attendance was the most consistent predictor of lung epithelium permeability. A positive dose-effect relation was found with cumulated pool attendance and serum SP-A and SP-B. Serum IgE was unrelated to pool attendance, but correlated positively with lung hyperpermeability as assessed by serum SP-B. Changes in serum levels of lung proteins were reproduced in children and adults attending an indoor pool. Serum SP-A and SP-B were significantly increased after one hour on the poolside without swimming. Positive EIB and total asthma prevalence were significantly correlated with accumulated pool attendance indices. Implications. Regular attendance at chlorinated pools by young children is associated with an exposure-dependent increase in lung epithelium permeability and increase in the risk of developing asthma, especially in association with other risk factors. It is postulated that increased exposure of children to chlorination products in indoor pools might be an important cause of the rising incidence of childhood asthma and allergic diseases in industrialized countries. Further epidemiological studies should be undertaken to test this hypothesis.

SWIMMING IN INDOOR POOLS ACCELERATES THE CONCENTRATION OF CHLORINATION CONTAMINANTS IN SWIMMERS

Aggazzotti, G., Fantuzzi, G., Righi, E., & Predieri, G. (1998). Blood and breath analyses as biological indicators of exposure to trihalomethanes in indoor swimming pools. Science of the Total Environment, 217, 155-163.
In this article, exposure to trihalomethanes (THMs) in indoor swimming pools as a consequence of water chlorination was reported.
Environmental and biological monitoring of THMs assessed the uptake of these substances after a defined period in competitive swimmers (N = 5), regularly attending an indoor swimming pool to train for competition during four sampling sessions. Analyses were performed by gas-chromatography and the following THMs were detected: chloroform (CHC13), bromodichloromethane (CHBrC12), dibromochloromethane (CHBrsC1) and bromoform (CHBr3). CHC13 appeared the most represented compound both in water and in environmental air before and after swimming. CHBrC1w and CHBr2C1 were always present, even though at lower levels than CHC13, CHBr3, was rarely present. In relation to biological monitoring, CHC13, CHBrC12 and CHBr2C1 were detected in all alveolar air samples collected inside the swimming pool. Before swimming, after one hour at rest at the pool edge, the mean values were 29.4 +/- 13.3, 2.7 +/- 1.2 and 0.8 +/- 0.8 micrograms/m3, respectively, while after spending one hour of swimming, higher levels were detected (75.6 +/- 18.6, 6.5 +/- 1.3 and 1.4 +/- 0.9 micrograms/m3, respectively). Only CHC13 was detected in all plasma samples (mean: 1.4 +/- 0.5 micrograms/1) while CHBrC1x and CHBr2C1 were observed only in few samples at a detection limit of 0.1 micrograms/1. After one at rest, at an average environmental exposure of approx. 100 micrograms/m3, the THM uptake was approx. 30 micrograms/h (26 micrograms/h for CHC1c, 3 micrograms/h for CHBrC12 and 1.5 micrograms/h for CHBr2C1). After one hour of swimming, the THM uptake was approximately seven times higher than at rest: a THM mean uptake of 221 micrograms/h (177 micrograms/h, 26 micrograms/h and 18 micrograms/h for CHC13, CHBrC12 and CHBr2C1, respectively) was evaluated at an environmental concentration of approx. 200 micrograms/m3.Implication. Training for swimming in a poorly ventilated indoor swimming pool has the potentialto cause illness through breathing undesirable concentrations of mainly chloroform.

CHLORINE PRODUCT ABSORPTION IN SWIMMERS IS GREATEST VIA THE SKIN

Lindstrom, A.B., Pleil, J.D., & Berkoff, D.C. (1997). Alveolar breath sampling and analysis to assess trihalomethane exposures during competitive swimming training. Environmental Health Perspectives, 105(6), 636-642
Alveolar breath sampling was used to assess trihalomethane (THM) exposures encountered by collegiate swimmers during a typical 2-hr training period in an indoor natatorium.
Breath samples were collected at regular intervals before, during, and for three hours after a moderately intense training session. Integrated and grab whole-air samples were collected during the training period to help determine inhalation exposures, and pool water samples were collected to help assess dermal exposures.
Resulting breath samples collected during the workout demonstrated a rapid uptake of two THMs (chloroform and bromodichloromethane), with chloroform concentrations exceeding the natatorium air levels within eight minutes after the exposure began. Chloroform levels continued to rise steeply until they were more than two times the indoor levels, providing evidence that the dermal route of exposure was relatively rapid and ultimately more important than the inhalation route in this training scenario. Chloroform elimination after the exposure period was fitted to a three compartment model that allowed estimation of compartmental half-lives, resulting minimum blood borne dose, and an approximation of the duration of elevated body burdens. It was estimated that dermal exposure route accounted for 80% of the blood chloroform concentration and the transdermal diffusion efficiency from the water to the blood was in excess of 2%. Bromodichloromethane elimination was fitted to a two compartment model that provided evidence of a small, but measurable, body burden of this THM resulting from vigorous swim training.
These results suggest that trihalomethane exposures for competitive swimmers under prolonged, high-effort training are common and possibly higher than was previously thought and that the dermal exposure route is dominant. The exposures and potential risks associated with this common recreational activity should be more thoroughly investigated.Implication. In this study the greater importance of transdermal (via the skin) uptake of chlorinated hydrocarbons compared to the respiratory route is demonstrated. This indicates that improved ventilation alone will not have a major impact on exposure to these materials because it is being immersed in the liquid that is the greatest threat. In contrast, ozonation allows markedly reduced levels of chlorine in the pool water.

EXERCISING INCREASES THE TOXICITY OF A "SAFE" CHLORINATED POOL ATMOSPHERE

Drobnic, F., Freixa, A., Casan, P., Sanchis, J., & Guardino, X. (1996). Assessment of chlorine exposure in swimmers during training. Medicine and Science in Sports and Exercise, 28(2), 271-274.
The presence of a high prevalence of bronchial hyperresponsiveness and asthma-like symptoms in swimmers has been recently reported. Chlorine, a strong oxidizing agent, is an important toxic gas that a swimmer can breath during training in chlorinated pools.
Measurements of the chlorine concentration in the breathing zone above the water (< 10 cm) were obtained randomly during five nonconsecutive days in four different swimming pool enclosures. The mean level in all the swimming pools was 0.42 +/- 0.24 mg/m3, far below the threshold limited value (TLV) of 1.45 mg/m3 for the work places for a day of work (8 h). The TLV could be reached and even exceeded if we consider the total amount of chlorine that a swimmer inhales in a daily training session of two hours (4-6 g) compared with a worker during eight hours at the TLV (4-7 g). Low correlation was observed with the number of swimmers in the swimming pool during the measurements (0.446) and other variables as the water surface area of the pool, volume of the enclosure, and the chlorine-addition system in the swimming pool. A low turnover rate in the air with an increase of chlorine levels through the day was observed in all pools.
The concentration of chlorine in the microenvironment where the swimmer is breathing is below the TLV concentration limit, but nevertheless results in a high total volume of chlorine inhaled by the swimmers in a given practice session.
The possible role of chlorine in producing respiratory symptoms in swimmers needs further investigation.Implication. Even though chlorine concentrations in a pool environment are at acceptable "safe" levels, it is a swimmer's exercising that produces abnormal levels of exposure to this toxin.
There has not been sufficient research to even begin understanding the health effects of this repetitive exposure.

AMOUNT OF EXERCISE IS RELATED TO CHLORINE-RELATED CONCENTRATIONS IN THE BODY

Cammann, K., & Hubner, K. (1995). Trihalomethane concentrations in swimmers' and bath attendants' blood and urine after swimming or working in indoor swimming pools. Archives of Environmental Health, 50(1), 61-65
The influence of working or swimming in indoor swimming pools on the concentrations of four trihalomethanes (haloforms) in blood and urine was investigated. Different groups (bath attendants, agonistic swimmers, normal swimmers, sampling person) were compared.
The proportions of trihalomethanes in blood and urine correlated roughly with those in water and ambient air. Higher levels of physical activity were correlated with higher concentrations. Within one night after exposure in the pool the blood concentrations usually were reduced to the pre-exposure values. Secretion of trichloromethane in urine was found to be less than 10%.Implication. Exercising in a chlorinated pool increases the levels of assimilation of chlorine related gases. The greater the amount of exercise, the greater the concentrations. Thus, hard training swimmers are at greater risk than more sedentary pool attendants and coaches.
It takes at least one night for absorbed substances to be removed. If insufficient time exists between training sessions the possibility of toxic build-up is real.

Re: Long term Health Effects

Are there any chemistry whizes out there that can answer this?....Are Chlorine and Dioxin simillar enough to cause the same effects in the human body?? Dioxin has been proven to cause endometriosis in women. It has also been linked to many other health problems....just curious!

Re: Long term Health Effects

Originally Posted by Daggles69

It takes at least one night for absorbed substances to be removed. If insufficient time exists between training sessions the possibility of toxic build-up is real.

Ok what does one night mean? 8 hours? 22hours? Or does something happen when you're sleeping to rid the body of toxins?
Just thinking if you're doing 2 a day at 5am and 5pm...is there a "night's worth" of time in there?

Re: Long term Health Effects

I can smell the chlorine the next day from my skin, and this maybe after 2 showers with complete washes with soap.

I also have cancer and I am fighting this from every direction I can. I am very fit, however I now understand cancer. I simply cant take the risk of adding to the long list of chemicals we are already exposed to.

Don't worry I will beat it, however I found the above study in my search for answer's.

If did not have cancer and lead a life that assisted in my bodies own immune system to fight against cancer buildup then I would continue to swim as I believe the benefit outweighs the risk.

It's all in moderation, however the lower the chlorine level the better!!

Re: Long term Health Effects

This is an old thread, wonder if there are folks, like me, interested in this topic? Any new development? If you swim 7 days a week, 1 hour each time, in a heavily chlorinated pool, does it take months or years for the serious harm to be done? The place where I swim, the pool is many floors up on top of the building (indoor pool), but you can already smell very strong chlorine at the building entrance on street level.

Re: Long term Health Effects

Originally Posted by ddl

This is an old thread, wonder if there are folks, like me, interested in this topic? Any new development? If you swim 7 days a week, 1 hour each time, in a heavily chlorinated pool, does it take months or years for the serious harm to be done? The place where I swim, the pool is many floors up on top of the building (indoor pool), but you can already smell very strong chlorine at the building entrance on street level.

I'm wondering if the street-level chlorine odor is an artifact of how the building is vented, espec if it is an older building.

I'm definitely not an expert, but my take on the above-referenced studies is that you probably do not have the type of exposure that would cause serious harm in a normal, healthy person. The one study I read on exposure in elite swimmers looked at those who swam exhaustively many hours a day. Perhaps it would help to reread the abstracts put up by "daggles69" and note the study groups: "competitive swimmers," "intense training," "two hours" (or more) per day, in a poorly ventilated pool area. If you are highly concerned or have a predisposing condition, you may be able to find a pool that does not use chlorine; the newer ones are more commonly using alternatives.

Re: Long term Health Effects

Originally Posted by ViveBene

I'm wondering if the street-level chlorine odor is an artifact of how the building is vented, espec if it is an older building.

The odor definitely comes from the pool. The building is very new. I do hope it takes years and years of intense training for the harm to be done. OTH given the very strong smell in this place perhaps a few months is bad enough. The smell of chlorine on my skin remains the next day like daggles69.

Re: Long term Health Effects

DDL,
I have found that showering BEFORE entering the pool greatly decreases the chlorine smell I carry around after swimming. Whether this indicates a decreased absorption of chlorine or is strictly anecdotal, I don't know. There may be no changes in health consequences but at least I don't smell like a washing machine after my wife washes the whites!

Re: Long term Health Effects

Hi
I'm writing an article on the safety of swimming pools, touching on some of the dangers of chlorine disinfecting products. In researching this, I came across your website and read some of the concerns expressed, by athletes, aquatics directors, and parents, having to do with various potential or imagined threats. My impression before this was that few people are even aware of these issues of asthma, respiratory ailments, skin rashes, eye infections, etc. etc.

In the aquatics field, do people think this is a serious issue that demands more study? Are parents of athletes in training, coaches, and swim clubs aware of these issues?

Re: Long term Health Effects

When I swam competitively there were 4 kids I knew whose doctors recommended competitive swimming because the kids had asthma. During the years I swam with them none of them had an asthma attack or carried an inhaler. AFAIK, they had no other issues.
While swimming 2x/day as well as having meets on weekends, no one I knew suffered any skin, eye, respiratory or other ailments. Everyone was, and continues to be, as healthy as the proverbial horse.
That said, I live in San Diego and always swam in outdoor pools. I don't know if that makes a difference...

**and a funny P.S....our family dog drank exclusively from our pool. She refused to drink out of a dog dish. The dog was never sick, died at 16, and had the whitest doggie teeth you have ever seen.

Re: Long term Health Effects

As usual some worry about how healthy life styles or endeavors might "not" be healthy. I got criticized for running long distances, even by a cardiologist! The sedentary people and even the overweight are sometimes critical and try to find some excuse for not doing exercises. Not your case, I hope. Back in the late 60s the swimming pools were loaded with chlorine, and we didn't have any eye protection. No one ever got hurt or had any health problems even while doing extensive practice in the pools. Nowadays, pools have pretty much a mixture in their sanitation process, using a blend of chemicals that one hardly perceives. I will add that even the sun exposure problem in outdoor pools is exaggerated. As an aside, there are many pool sanitation methods that do not use chlorine.

Re: betchurlife I'll be there

There's no doubt that too much chlorine exposure is bad. If you have access to a lake or ocean nearby that would help mix it up every once in a while. Also to help balance the chlorine absorbed into your system through your skin there are herbs and minerals you can take (balance your own pH out, just like the pool).

Re: Long term Health Effects

Flyman,
As the original poster of this thread, I cheer you on with your studies. Knowledge is power and we don't seem to have a lot of science on this. My gut tells me the safety question is highly variable depending on the composition of the "soup" we swim in, the external environment in the pool area, time spent in contact, pre-shower vs. no shower, de-chlorinating rinses and lotions, and on and on. I still believe the health benefits outweigh the risks but vigilance is warranted. I'm sure running is a very healthy activity but I wouldn't recommend doing it on the interstate or in Chernobyl. Besides, you might get something published that would be of interest to somebody. I had a professer once that said "The definition of a drug is any compound which, upon injection into a laboratory rat, generated a paper". Good Luck!